The present invention relates generally to a magnetic tape cartridge for use as a data storage media. More specifically, the invention relates to a magnetic tape cartridge compatible with a disk drive and being particularly useful as backup storage media for a computer. Further particularly, the invention relates to a tape drive mechanism for a disk-drive-compatible magnetic tape cartridge, which tape drive mechanism requires very little vertical clearance within a cartridge casing and can steadily drive the tape.
As is well known, magnetic tape has a relatively large data storage capacity. Magnetic tape is especially useful as a storage medium when fast access is not required, such as when used for backup storage. However, on the other hand, because of the relatively slow access of the desired data, tape is less popular than disk-type storage media, such as floppy disks, hard disks and so forth. Therefore, recent computers generally employ disk-based data storage systems as built-in or external units.
Various floppy disks and disk drives designed for use with associated disks have been developed and proposed. For example, the U.S. Pat. No. 4,445,155, issued on Apr. 24, 1984, to Takahashi et al discloses a typical construction of a microfloppy disk, i.e. a 3.5-inch floppy disk and a disk drive therefor. The floppy disk is in the form of a floppy disk cassette or cartridge generally comprising a flexible magnetic disk and a cassette or cartridge casing. The flexible disk includes a center core disk designed to be chucked on a turntable of the disk drive. The disk drive drives the flexible disk and the center core disk to rotate.
The floppy disks are useful for fast access. On the other hand, floppy disks have limited data storage capacity. Archival or backup storage of data stored on a hard disk generally takes 20 to 80 floppy disks due to their larger capacity. This involves substantial expense for the user. On the other hand, magnetic tape can easily accommodate all of the data stored on a hard disk, as is well known. However, a special tape recording and/or reproducing apparatus has previously been necessary for copying data from the hard disk onto the magnetic tape storage medium. This is an additional expense for the user.
So as to allow the user to utilize magnetic tape for inexpensive backup storage of data on hard disks or floppy disks, it would be beneficial to provide a magnetic tape cartridge compatible with floppy disk drives so that it may be driven by the same drive unit as floppy disks.